Department of Biology, C-016, University of California at San Diego, La Jolla, California 92093.
Plant Physiol. 1983 Nov;73(3):576-8. doi: 10.1104/pp.73.3.576.
The leaves of Phaseolus vulgaris L. cv Greensleeves contain an endopeptidase with a pH optimum of 9.0 and an isoelectric point between 10.0 and 10.5. This endopeptidase is the only abundant Azocoll-digesting proteinase in the leaves. The activity of this enzyme is highest in immature leaves and declines as the leaf matures and senesces. Enzymically isolated protoplasts contain very little of this proteinase. The proteinase can be recovered readily from the extracellular fluid obtained by gentle centrifugation of leaf strips vacuum-infiltrated with a buffered solution. These experiments indicate that the Azocoll digesting proteinase is located in the periplasmic space and/or the cell wall.
菜豆（Phaseolus vulgaris L. cv Greensleeves）叶片含有一种内切酶，其最适 pH 值为 9.0，等电点在 10.0 到 10.5 之间。这种内切酶是叶片中唯一丰富的 Azocoll 消化蛋白酶。该酶在未成熟叶片中的活性最高，随着叶片的成熟和衰老而下降。通过酶解分离的原生质体中含有很少的这种蛋白酶。该蛋白酶可以从经缓冲溶液真空渗透处理的叶片条带经温和离心获得的细胞外液中轻易回收。这些实验表明，Azocoll 消化蛋白酶位于周质空间和/或细胞壁中。
